This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Allergy to inhaled allergens is a major cause of allergic diseases (e.g. asthma, hay fever) that affect up to 30% of some populations. Asthma is one of the most common chronic diseases. Women represented 70% of all US adults hospitalized for asthma. Several recent observations strongly implicate female hormones as a cause for these differences. Women taking hormone replacement therapy (HRT) after menopause are more likely to develop asthma, compared to those that do not take hormones. Finally, in 30-40% of women with asthma note their asthma is worse around the time of their menstrual periods. The long-term goal of our research is to understand the role for female hormones in the development and worsening of asthma and other allergic diseases. The current proposal is to analyze the changes of allergic reactions during the menstrual cycle, and relate these to the concentrations of female hormones promote allergic reaction and airway hyperreactivity. Each patient will be requested to make three visits to GCRC outpatient facility. These will be timed so they are likely to be during perimenstrual phase, near ovulation and after ovulation. We will do skin testing, draw blood and measure lung functions using spirometer at the GCRC outpatient facility. Estrogen and progesterone will be measured at the UTMB Hospital Clinical Chemistry Lab, and measurement of allergic degranulation in the investigator's Lab. Successful completion of this project will provide a new understanding of effects on female hormones to allergic reactions. This data will help us to develop new therapeutic approaches for managing allergic disease during different phases of menstrual cycle.